Mine was acting like that too. I had to buy a whole new switch from the dealer, but I don't think it was all that expensive. Mine was melted some on the back side. If yours is, you'll probably need to replace it.

I found out for sure it was the switch by removing it and jumping a wire to all of the speeds on the back of the connector and they all worked, so I knew it was the switch.

 

check for this on the back of your blower motor on the passenger side footwell. i ended up cutting a connector from a junk yard tj.

 

Its your "blower motor resistor". It needs to be changed. Its not hard to do, but its a PITA.

 

Mine acted similar and it was the switch assembly, not the resistor. Like I said earlier, just pull the switch assembly out, disconnect the connector on the back and use a wire to jump from ground to each wire (speed). If they all work, it's the switch. If they don't, it's probably the resistor.

 

It's not the resistor, the resistor only controls settings 1-3. Check the dash switch and relay.

 

I beg to differ.

 

Check the 40a fuse (#11) in the PDC under the hood, and the blower relay mounted on the a/c box under the dash. Both are used for High blower speed only. Lower speeds use fuse 8 in the fuse block.
If the connector for the switch is melted, it could be a sign that the fan motor is drawing too many amps and is close to the end of its life. I'd replace the connector and have the fan motor amp draw tested.

Curly

 

All fuses are ok, but thanks Curly. Let me do some testing at the switch, see if the switch is bad. Like Freeskier93 said, I think when the resister goes back, settings 1 - 3 do not work but 4 does work. I'm having just the opposite. I don't believe the resister comes in to play on setting 4; I think it just lets the fan full-power. Maybe it's something with the switch or wiring. When I switch it to 4, I can hear the relay click off.

Thanks all; I'll try to let you know how I make out.

 

Mine did the same thing, if I pushed in on the switch high would work. I got a new switch for 24$ from a dealership and it's been working fine for a couple years now.

 

I was told by the dealer the switch is not available. They said it was part of the entire control. Do you have A/C? Do you have the part number?

 

I don't think it is the blower resistor, and here's why. I have a melted resistor harness clip just like pictured above, and a bad resistor switch. The resistor switch knocks out speeds 1-3 when dead. Mine is not even plugged in right now, as I have not re-wired it or replaced the resistor. My High speed works fine.

without looking at the diagram, I think the way it works is that the switch supplies direct current to the motor on '4', but shunts it though the resistor for 1-3. based on the wire feed for the motor, which i also checked, this seems to make sense.

 

I think the way it works is that the switch supplies direct current to the motor on '4', but shunts it though the resistor for 1-3. based on the wire feed for the motor, which i also checked, this seems to make sense.

The HVAC switch supplies resistive ground, not power for the blower motor in positions 1, 2 and 3...

 

The switch activates a relay in position 4 (high), the relay feeds the blower off of a 40 amp fuse in the PDC, seperate from the fuse for the lower speeds.

Curly

 

Fan speeds 1 and 4 dont work in mine. any ideas for whats causing that?

 

Bump

 

Fan speeds 1 and 4 dont work in mine. any ideas for whats causing that?

Have you checked power and resistance when using those settings? Get out the multimeter and check the resistance at at the fan for each of the settings on the switch. Make sure some voltage is coming through the resistor, then go test before the resister, and at the switch. That will tell you if its the resistor or switch.

 

if the lowest fan speed works....its the blower motor resistor...then the blower motor itself.

 

In my wife's 97 TJ, the high speed wasn't working. Everything checked out electrically. I held the relay (behind glove box, next to fuse panel) and could hear and feel it click/transition when I turned the switch to high. Turns out the relay socket had melted at the red wire (power feed from fuse 11 for high speed). Jumper from Red to Dark Green (no stripe) and the blower works fine. New socket on its way. If it melts again, and depending how quick, I would look at replacing the blower motor. I also need to check if there's a filter in the path. A dirty filter would would cause the blower to pull more amps.

 

thanks!

that was exactly the problem I had, no hi speed on my blower even tho I had just replaced resistor to fix no low speed problems. had been hot wiring fan for years. put resistor in and low speeds worked great but no hi speed.

found relay behind glove box just as mentioned above, had a bad connection. jumped between red and green wire and blower ran on hi speed fine. cleaned all terminals and relay plug with electric contactor cleaner and put relay back in and it works great on all speeds now!

 

The switch aka climate control on dash is bad had same problem and it worked after changing climate control, the resistor usually cause a problem in the reverse of that

 

Aug 6, 2020